Adding a photo to memojis

You can only add the main subject of a photo to the stickers and can use it to decorate your messages, see: Make stickers from your photos on iPhone – Apple Support (UK)

But this will remove the background of the subject. It is not possible to use the complete photo as a sticker.

Cool idea, but no, I'm afraid not.

Emoji are like extensions of the alphabet. There's A B C and 😵‍💫. Like A and B and C, 😵‍💫 has a particular text code that is internationally agreed on.

So when someone sends the word CAT, they're really sending 3 numbers that tell which 3 symbols in the alphabet to use. And CAT may look different on your computer than on mine, because your computer can draw those three numbers any way it wants-- maybe in Russian or Arabic, for instance, or in Times New Roman or in Helvetica.

In the same way, when I type 😵‍💫, I've sent you a number representing a symbol in the alphabet (way more than 26!), and it may look different on your computer. But, because of international standards, it will look like a "face with spiral eyes," even if that might be a little different from mine.

So, if you drew your own picture and assigned it a number, no other computer in the world would know what to draw. Unless you can get international agreement, of course.

Wow-- missed one little letter...